SELECT
    ROUND(AVG(TOTAL_VALUE)) AS 'SA_MEDIAN'
FROM 
    (SELECT
        TOTAL_VALUE
    FROM CONVENIENCE
    WHERE
        KIND_CODE = '100'
        AND SURVEY_YEAR = 2019
    ORDER BY TOTAL_VALUE
    LIMIT
        2 - (SELECT COUNT(*) FROM CONVENIENCE) % 2
    OFFSET
        (SELECT (COUNT(*)-1)/2 FROM CONVENIENCE)
    )